(Hyper) branched polymers, with the characteristics of low viscosity, high dissolvability and high degree of functionality because of their unique 3D spherical structure, are believed to be amenable for extensive use as viscosity modifier of polymer melt in a number of fields, to prepare coating materials and adhesives with high solids content, carriers of drugs, catalysts, and liquid crystal polymers and photoelectrical materials. It has become a popular subject in the polymer science, as their prospects of application have attracted large numbers of domestic and overseas experts and scholars to investigate them.
Currently, the main processes to synthesizing vinyl branched polymers are live polymerization and conventional free radical polymerization with chain transfer agent. However, live polymerization requires very severe reaction conditions, and the polymerization reaction cost is very high, with limited types of suitable monomers. Compared with live polymerization, conventional free radical polymerization reaction is simple and easy, however, the conventional free radical polymerization reaction systems reported are quite complicated, and large amount of additional agent should be added; the (hyper) branched polymers obtained from the synthesis have low molecular weight with wide distribution; the branching points of the products are weak chemical bonds; the branched monomers themselves are extremely unstable, and the speed and degree of potential branched monomers releasing branched groups are restricted by several factors. These deficiencies have seriously restricted the theoretical research and scaled applications of vinyl branched polymers.
Discovering a simple and cheap synthesizing processes is an important orientation of research of vinyl branched polymers. In this invention, a new type of free radical polymerization initiator containing a polymerisable double bond and peroxide bond is designed to synthesize vinyl monomers into branched polymers under the conventional free radical polymerization, without addition of branched monomer. This invention has important significance to the theoretical research and scaled applications of (hyper) branched polymers.